Citrus crops including Citrus sinensis Sweet Oranges are important to the agricultural economy in many parts of the world. Among Citrus plants commonly grown in California and Texas, U.S.A., is the ‘Valencia Late’ orange cultivar (non-patented in the United States) which is well recognized for its quality fruit.
The new cultivar of Citrus sinensis of the present invention was discovered during 1999 as a single branch mutation on a tree of the ‘Valenica Late’ cultivar at L'Alcudia de Crespins, Valencia, Spain. The discovery was made in a nursery setting consisting of trees of the ‘Valencia Late’ cultivar. The new cultivar is believed to be a significant mutation of the ‘Valencia late’ cultivar of unknown causation.
I was primarily attracted to a single plant of the new cultivar in view of its distinctive fruit and leaf characteristics which were substantially different than those of the ‘Valencia Late’ cultivar. Had I not discovered and preserved the single branch of the new cultivar it would have been lost to mankind.
The new cultivar displays characteristics of both an Orange tree and a Tangerine tree.
It was found that the new Orange Tree of the present invention possesses the following combination of characteristics:                (a) forms attractive large seedless fruit which when compared to that of the ‘Valencia Late’ cultivar bears a lighter yellow-orange external coloration, a generally more flattened configuration, commonly a greater diameter, and peels more readily,        (b) forms larger leaves which generally are more rounded in configuration and less elongated than those of the ‘Valencia Late’ cultivar,        (c) bears late-maturing fruit that matures for consumption at approximately the same time as that of the ‘Valencia late’ cultivar, and        (d) is well suited for the commercial production of a fruit crop.        
The new cultivar of the present invention also can be readily distinguished from the ‘Nova’ cultivar (non-patented in the United States). More specifically, the ‘Nova’ cultivar forms smaller fruit, and the leaves are smaller and more elongated.
The new cultivar of the present invention has been found to undergo asexual propagation at Valencia, Spain, by the rooting of cuttings and by grafting. Such asexual propagation has been shown that the charateristics of the new cultivar are strictly transmissible from one generation to another. Accordingly, the new cultivar undergoes asexual propagation in a true to type manner.
The new cultivar has been named ‘Alvarina’.